This invention relates in general to machines for forming toroids, or doughnuts, from fairly heavy, tacky dough employed in the bagel making industry. More specifically, the present invention relates to such a machine which employs a plurality individual forming members mounted on a revolving conveyor which cooperate with a stationary mandrel to form dough bodies in the form of toroids suitable for making bagels, doughnuts, or the like.
Various types of machines for automatically forming dough into toroids for subsequent proofing and baking have been developed heretofore and are in use commercially. In one type of such machines, a continuous belt is drawn through a stationary tube having a dough forming mandrel positioned centrally thereof to form dough strips into toroid configuration. An advantage of the belt type bagel making machine is that the belt, associated mandrel and sleeve through which the belt passes can be switched on any particular machine to provide for the making of different size bagels. Such machines are also generally less expensive to construct than the rigid cup type machines discussed hereinafter. A disadvantage of the belt machines is that belts tend to wear out in any where from three to six months time. The belt is mounted on associated pulleys which drive the belt from a generally flat configuration into the sleeve whereby it is formed into a cylindrical configuration about the stationary mandrel. Also, as the belt exits the surrounding sleeve it attempts to quickly resume its flat configuration, since its being pulled by an associated pulley. This closing and opening of the belt as it enters and leaves the surrounding forming sleeve tends to wear the belt accordingly. In addition, the length of this type of machine is necessarily fairly long in order to allow for the closing and opening of the belt as it approaches and leaves the forming sleeve within which the dough bodies are formed. Exemplary of such prior art machines are the U.S. Pat. Nos. 1,552,430, 1,755,921 and 2,666,398.
Other types of prior bagel making machines have used metal forming cups which are manipulated by the apparatus as opposed to the use of a belt for forming bagels as mentioned above. One approach is shown in the Ritter U.S. Pat. No. 3,379,142 where a plurality of half cups are provided on two opposed conveyors arranged so that the cups come together around a stationary mandrel to form dough therebetween. Another approach has been to use a single conveyor having metal cups of cylindrical configuration which are themselves articulated by virtue of being in three relatively hinged rigid pieces which are guided during the forming operation by associated tracks as the cups pass a stationary mandrel. Exemplary thereof are my prior Pat. Nos. 3,031,979; 3,433,182; 3,792,940; 3,986,446; 4,147,809; 4,218,207; 4,368,019; and 4,478,565. Machines for making bagels or other dough products in toroid configuration employing metal cups as in these patented machines have the advantage of long life. However the metal forming cups from a practical standpoint must be coated with a plastic material so as to prevent the dough from adhering thereto. Sometimes the plastic coating on the cups tends to wear and the cups must be removed for sandblasting and then recoating before being replaced. Also, while these metal cup forming member machines can be made in relatively short length for convenience of their location in a commercial bakery environment, they are limited to making a single size of dough product determined by the size of the forming cups.
I am also aware of a prior art toroid forming means employed prior to my present application in a commercial establishment known as the Bagel Factory in Los Angeles, California.